1. Field of Invention
This invention relates to electrical power adapters, and more particularly to an automatic polymer adapter for supplying electrical power to a marine vessel or vehicle load from a pair of combined lower amperage capacity sources. The power sources can be selectively and automatically electrically connected and applied to the load to increase the current capacity depending on the sensed configuration and phase alignment of the input power sources.
2. Description of the Prior Art
The prior art addresses the application of land or dock electrical power sources to marine vessels. When marine craft are moored alongside a dock or seawall electrical power is usually, supplied from shore side power sources that may have circuits with lower amperage capacities than the craft requires. It is common practice to use adapters of various types to collect two lower amperage circuits into one higher amperage circuit. The most basic type of adapters have no safety provisions, such as protecting the exposed blades of an unattached plug which can cause dangerous shocks and burns, or protection against incorrect phase matching of the shore side power connections, which can result in shorts, blown fuses and/or tripped circuit breakers. Some phase-sensing units do have the capabilities to avoid the potential safe hazards and shorts, but if the phases are not aligned properly at the shore-side power supplies the units will not be enabled and will not allow power to pass through or be supplied to the craft without the requirement of additional adapters, or alternatively rewiring the shore-side power supplies. Some existing phase-sensing units may have capabilities to switch the phases manually, but not automatically through circuitry set forth in the instant inventions.
For example, U.S. Pat. No. 4,204,243 issued to Ross is entitled “Polarity Indicating and Reversing Unit”, and discloses an adapter device which senses and indicates a reverse polarity condition for internal wiring at a power supply or load, such as an appliance, tool, mobile home, trailer or extension cord. The device is also used to connect two two-wire plus ground power supply lines each having a neutral and a hot, inlet conductor to a single three-wire plus ground load line having a common neutral and two hot outlet conductors. However, once an undesired polarity condition is detected, an operator must utilize one of two manual switches to reverse the polarity of either of the inlet lines to a common outlet line. The unit also has an automatic disconnect feature to electrically disconnect either of the inlet plugs from the unit when a power supply line is not connected to that inlet plug, but will allow operation when one plug is connected.
U.S. Pat. No. 5,160,852 issued to Charles et al. is entitled “Power Adapter”, and teaches a circuit design used to connect a marine vessel or other mobile electrical load to stationary power sources including those provided on power supply pedestals in marinas. This adapter is used to connect a pair of 120 volt sources to a higher voltage load, such as a 240 volt load used on many boats. This design includes an isolation circuit to avoid electrical shock, and a pair of diode bridge networks. A sensing means within this adapter determines if the power sources are in proper relationship, such as out-of-phase 120 volt supplies for summing voltage or in phase supplies for summing current. If the predetermined proper relationship is established, an output means is driven and enabled for electrical connection to the load. However, if a proper relationship in not determined, the adapter is disabled, and no output is generated to the load. Indicator lights are used to indicate a fault condition to the user, as well as the nature of the problem. The adapter does not correct or compensate for improper phase relationships, and simply prevents operation of the unit. The user is left to correct the problems through rewiring of sources, use of additional adapters or the like.
U.S. Pat. No. 5,245 219 issued to Romatzick, Jr. et al is entitled “Marine Power Y-Adapter”, and discloses a Y adapter for interfacing with a dockside power center having two conventional receptacles and having two three-pole plugs and a third four-pole plug for connecting to the load/marine vessel, the latter being phase conductors L1 and L2 along with neutral and ground conductors. This device is disabled if one dockside male plug is not inserted into a receptacle or is removed. The Y adapter also supplies voltage equal to the sum of the input voltages to the vessel when the sensor and control means is responsive to a pre-determined difference in voltage between phase conductors. If the phases or polarities sensed are not proper, or if there is an improper wiring condition at the dockside receptacles, the adapter indicates a fault condition and does not pass voltage to the output connector or marine vessel. Although the user is alerted to the incompatible conditions and lack of power to the vessel, the Y adapter does not correct or compensate for the problems or improper wiring. Re-wiring or the use of separate equipment is required.
Lastly, U.S. Pat. No. 5,302,857 is to Charles et al., is entitled “Portable Power Adapter”, and depicts circuit designs for connecting a 240 volt load/marine vessel to a pair of 120 volt sources such as those provided in marinas. The circuitry includes isolation means for isolating the input connectors from one another during connection operation, sensing means for determining that the sources are in proper phase relationship, and summing means for providing the multiple power inputs to a driven load. The adapter disclosed protects the operator and advises as to the operability and status of the adapter and connections when predetermined conditions are satisfied If conditions are not met, indicating improper phase relationships, voltages, polarity, tripped breakers or the like the adapter indicates it's inoperative and fault detection status. In this mode, power is not supplied to the output of the adapters or to the marine vessel. Although the nature of the problem is indicated in part as with other prior art devices, this adapter and circuitry does not contain any internal components capable of automatically correcting, the problems, compensating for phase relationships or mis-wiring, aid summing the amperage in a desired fashion to remain operable and power the craft.
The automatic power adapter of the instant invention has protective features to safely avoid shocks and burns, to sense the alignment of all phases, and to automatically and internally align the phases if necessary, and connect the circuits correctly without any additional switches or adapters.
It is therefore an object and feature of the instant inventions to provide a power adapter which can pass through independent voltage and current input sources, automatically detecting and compensating for any necessary, phase alignments, and summing the amperage available for output to a load or marine vessel.
It is further an object and feature of the instant inventions to provide an automatic power adapter which is responsive to a variety of different wiring phase, voltage, polarity or circuit breaker conditions of two input power sources, automatically, compensate and take corrective actions to maintain proper voltage and sum current capacity, and provide a single desired output without any actions required on the part of an operator or user.
It is further an object and feature of the instant inventions to provide a heavy duty automatic power adapter for large load maine vessels which incorporates inherent safety features, provides status indicators eliminates the need for auxiliary equipment or adapters, and is cost effective to manufacture and is operationally efficient.
Finally, it is desirable to provide and automatic power adapter having all of the objects and features mentioned above.